Organic electroluminescent materials and devices

ABSTRACT

Novel compounds containing benzothiophene or benzofuran fused to a carbazoles moiety are disclosed. The compounds are substituted such that both an electron donor fragment and an electron acceptor fragment are present within the same molecule. The compounds are capable of exhibiting delayed fluorescence when used in the emissive layer of OLED devices.

The claimed invention was made by, on behalf of, and/or in connection with one or more of the following parties to a joint university corporation research agreement: Regents of the University of Michigan, Princeton University, The University of Southern California, and the Universal Display Corporation. The agreement was in effect on and before the date the claimed invention was made, and the claimed invention was made as a result of activities undertaken within the scope of the agreement.

FIELD OF THE INVENTION

The present invention relates to a device containing compounds with benzothiophene or benzofuran fused to carbazole. The compounds contain an electron donor and an electron acceptor in the same molecule and can exhibit delayed fluorescence characteristics when used as emitters in OLEDs.

BACKGROUND

Opto-electronic devices that make use of organic materials are becoming increasingly desirable for a number of reasons. Many of the materials used to make such devices are relatively inexpensive, so organic opto-electronic devices have the potential for cost advantages over inorganic devices. In addition, the inherent properties of organic materials, such as their flexibility, may make them well suited for particular applications such as fabrication on a flexible substrate. Examples of organic opto-electronic devices include organic light emitting devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, the organic materials may have performance advantages over conventional materials. For example, the wavelength at which an organic emissive layer emits light may generally be readily tuned with appropriate dopants.

OLEDs make use of thin organic films that emit light when voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in applications such as flat panel displays, illumination, and backlighting. Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.

One application for phosphorescent emissive molecules is a full color display. Industry standards for such a display call for pixels adapted to emit particular colors, referred to as “saturated” colors. In particular, these standards call for saturated red, green, and blue pixels. Color may be measured using CIE coordinates, which are well known to the art.

One example of a green emissive molecule is tris(2-phenylpyridine) iridium, denoted Ir(ppy)₃, which has the following structure:

In this, and later figures herein, we depict the dative bond from nitrogen to metal (here, Ir) as a straight line.

As used herein, the term “organic” includes polymeric materials as well as small molecule organic materials that may be used to fabricate organic opto-electronic devices. “Small molecule” refers to any organic material that is not a polymer, and “small molecules” may actually be quite large. Small molecules may include repeat units in some circumstances. For example, using a long chain alkyl group as a substituent does not remove a molecule from the “small molecule” class. Small molecules may also be incorporated into polymers, for example as a pendent group on a polymer backbone or as a part of the backbone. Small molecules may also serve as the core moiety of a dendrimer, which consists of a series of chemical shells built on the core moiety. The core moiety of a dendrimer may be a fluorescent or phosphorescent small molecule emitter. A dendrimer may be a “small molecule,” and it is believed that all dendrimers currently used in the field of OLEDs are small molecules.

As used herein, “top” means furthest away from the substrate, while “bottom” means closest to the substrate. Where a first layer is described as “disposed over” a second layer, the first layer is disposed further away from substrate. There may be other layers between the first and second layer, unless it is specified that the first layer is “in contact with” the second layer. For example, a cathode may be described as “disposed over” an anode, even though there are various organic layers in between.

As used herein, “solution processable” means capable of being dissolved, dispersed, or transported in and/or deposited from a liquid medium, either in solution or suspension form.

A ligand may be referred to as “photoactive” when it is believed that the ligand directly contributes to the photoactive properties of an emissive material. A ligand may be referred to as “ancillary” when it is believed that the ligand does not contribute to the photoactive properties of an emissive material, although an ancillary ligand may alter the properties of a photoactive ligand.

As used herein, and as would be generally understood by one skilled in the art, a first “Highest Occupied Molecular Orbital” (HOMO) or “Lowest Unoccupied Molecular Orbital” (LUMO) energy level is “greater than” or “higher than” a second HOMO or LUMO energy level if the first energy level is closer to the vacuum energy level. Since ionization potentials (IP) are measured as a negative energy relative to a vacuum level, a higher HOMO energy level corresponds to an IP having a smaller absolute value (an IP that is less negative). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) having a smaller absolute value (an EA that is less negative). On a conventional energy level diagram, with the vacuum level at the top, the LUMO energy level of a material is higher than the HOMO energy level of the same material. A “higher” HOMO or LUMO energy level appears closer to the top of such a diagram than a “lower” HOMO or LUMO energy level.

As used herein, and as would be generally understood by one skilled in the art, a first work function is “greater than” or “higher than” a second work function if the first work function has a higher absolute value. Because work functions are generally measured as negative numbers relative to vacuum level, this means that a “higher” work function is more negative. On a conventional energy level diagram, with the vacuum level at the top, a “higher” work function is illustrated as further away from the vacuum level in the downward direction. Thus, the definitions of HOMO and LUMO energy levels follow a different convention than work functions.

More details on OLEDs, and the definitions described above, can be found in U.S. Pat. No. 7,279,704, which is incorporated herein by reference in its entirety.

SUMMARY OF THE INVENTION

A first device comprising a first organic light emitting device comprising an anode, a cathode, and an emissive layer, disposed between the anode and the cathode. The emissive layer comprises a first emitting compound having the formula G¹-Z, Formula I. G¹ is an electron acceptor group and Z is an electron donor group.

Z has the formula:

Formula II, where G² has the structure

and G² is fused to any two adjacent carbon atoms on ring A. X is selected from the group consisting of O, S, and Se, R¹ represents mono-, di-substitution, or no substitution. R², and R³ independently represent mono-, di-, tri-, or tetra-substitution. R¹ is optionally fused to ring A, R² is optionally fused to ring B, and R³ is optionally fused to ring C. R¹, R² and R³ are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, G¹ comprises at least one chemical group selected from the group consisting of:

wherein A¹ to A⁶ independently comprise C or N, and at least one of A¹ to A⁶ is N. J¹ to J⁴ independently comprise C or N, and at least one of J¹ to J⁴ is N. X¹ is O, S, or NR. R is selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, G¹ comprises at least one chemical group selected from the group consisting of:

E¹ to E⁸ independently comprise C or N, L¹ to L⁴ independently comprise C or N, and X² is O, S, or NR. R is selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, R³ is alkyl or aryl. In one aspect, Z comprises at least one chemical group selected from the group consisting of:

where, R¹¹, R¹², and R¹³ are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, Z comprises a least one chemical group selected from the group consisting of:

In one aspect, G¹ comprises at least one chemical group selected from the group consisting of:

wherein R²¹, R²², and R²³ are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, G¹ comprises at least one chemical group selected from the group consisting of:

In one aspect, G¹ comprises at least one chemical group selected from the group consisting of:

In one aspect, the compound is selected from the group consisting of Compound 1-Compound 22.

In one aspect, the first device emits a luminescent radiation at room temperature when a voltage is applied across the first organic light emitting device, where the luminescent radiation comprises a delayed fluorescent process.

In one aspect, the emissive layer further comprises a first phosphorescent emitting material.

In one aspect, the emissive layer further comprises a second phosphorescent emitting material.

In one aspect, the emissive layer further comprises a host material.

In one aspect, the first device emits a white light at room temperature when a voltage is applied across the organic light emitting device.

In one aspect, the first emitting compound emits a blue light having a peak wavelength between about 400 nm to about 500 nm.

In one aspect, the first emitting compound emits a yellow light having a peak wavelength between about 530 nm to about 580 nm.

In one aspect, the first device comprises a second organic light-emitting device, wherein the second organic light emitting device is stacked on the first organic light emitting device.

In one aspect, the first device is a consumer product. In one aspect, the first device is an organic light-emitting device. In one aspect, the first device comprises a lighting panel.

In one aspect, a method of making a first organic light emitting device, comprising depositing an anode on a substrate, depositing at least one organic layer comprising a compound of formula G¹-Z, Formula I. G¹ is an electron acceptor group and Z is an electron donor group.

Z has the formula:

Formula II, where G² has the structure

and G² is fused to any two adjacent carbon atoms on ring A. X is selected from the group consisting of O, S, and Se, R¹ represents mono-, di-substitution, or no substitution. R², and R³ independently represent mono-, di-, tri-, or tetra-substitution. R¹ is optionally fused to ring A, R² is optionally fused to ring B, and R³ is optionally fused to ring C. R¹, R² and R³ are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof, depositing a cathode. The emissive layer is deposited between the anode and cathode.

In one aspect, the at least one organic layer is deposited using a solution process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an organic light emitting device.

FIG. 2 shows an inverted organic light emitting device that does not have a separate electron transport layer.

FIG. 3 shows an exemplary compound of Formula I.

DETAILED DESCRIPTION

Generally, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the organic layer(s). The injected holes and electrons each migrate toward the oppositely charged electrode. When an electron and hole localize on the same molecule, an “exciton,” which is a localized electron-hole pair having an excited energy state, is formed. Light is emitted when the exciton relaxes via a photoemissive mechanism. In some cases, the exciton may be localized on an excimer or an exciplex. Non-radiative mechanisms, such as thermal relaxation, may also occur, but are generally considered undesirable.

The initial OLEDs used emissive molecules that emitted light from their singlet states (“fluorescence”) as disclosed, for example, in U.S. Pat. No. 4,769,292, which is incorporated by reference in its entirety. Fluorescent emission generally occurs in a time frame of less than 10 nanoseconds.

More recently, OLEDs having emissive materials that emit light from triplet states (“phosphorescence”) have been demonstrated. Baldo et al., “Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices,” Nature, vol. 395, 151-154, 1998; (“Baldo-I”) and Baldo et al., “Very high-efficiency green organic light-emitting devices based on electrophosphorescence,” Appl. Phys. Lett., vol. 75, No. 3, 4-6 (1999) (“Baldo-II”), which are incorporated by reference in their entireties. Phosphorescence is described in more detail in U.S. Pat. No. 7,279,704 at cols. 5-6, which are incorporated by reference.

FIG. 1 shows an organic light emitting device 100. The figures are not necessarily drawn to scale. Device 100 may include a substrate 110, an anode 115, a hole injection layer 120, a hole transport layer 125, an electron blocking layer 130, an emissive layer 135, a hole blocking layer 140, an electron transport layer 145, an electron injection layer 150, a protective layer 155, a cathode 160, and a barrier layer 170. Cathode 160 is a compound cathode having a first conductive layer 162 and a second conductive layer 164. Device 100 may be fabricated by depositing the layers described, in order. The properties and functions of these various layers, as well as example materials, are described in more detail in U.S. Pat. No. 7,279,704 at cols. 6-10, which are incorporated by reference.

More examples for each of these layers are available. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Pat. No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F₄-TCNQ at a molar ratio of 50:1, as disclosed in U.S. Patent Application Publication No. 2003/0230980, which is incorporated by reference in its entirety. Examples of emissive and host materials are disclosed in U.S. Pat. No. 6,303,238 to Thompson et al., which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1, as disclosed in U.S. Patent Application Publication No. 2003/0230980, which is incorporated by reference in its entirety. U.S. Pat. Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entireties, disclose examples of cathodes including compound cathodes having a thin layer of metal such as Mg:Ag with an overlying transparent, electrically-conductive, sputter-deposited ITO layer. The theory and use of blocking layers is described in more detail in U.S. Pat. No. 6,097,147 and U.S. Patent Application Publication No. 2003/0230980, which are incorporated by reference in their entireties. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety. A description of protective layers may be found in U.S. Patent Application Publication No. 2004/0174116, which is incorporated by reference in its entirety.

FIG. 2 shows an inverted OLED 200. The device includes a substrate 210, a cathode 215, an emissive layer 220, a hole transport layer 225, and an anode 230. Device 200 may be fabricated by depositing the layers described, in order. Because the most common OLED configuration has a cathode disposed over the anode, and device 200 has cathode 215 disposed under anode 230, device 200 may be referred to as an “inverted” OLED. Materials similar to those described with respect to device 100 may be used in the corresponding layers of device 200. FIG. 2 provides one example of how some layers may be omitted from the structure of device 100.

The simple layered structure illustrated in FIGS. 1 and 2 is provided by way of non-limiting example, and it is understood that embodiments of the invention may be used in connection with a wide variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures may be used. Functional OLEDs may be achieved by combining the various layers described in different ways, or layers may be omitted entirely, based on design, performance, and cost factors. Other layers not specifically described may also be included. Materials other than those specifically described may be used. Although many of the examples provided herein describe various layers as comprising a single material, it is understood that combinations of materials, such as a mixture of host and dopant, or more generally a mixture, may be used. Also, the layers may have various sublayers. The names given to the various layers herein are not intended to be strictly limiting. For example, in device 200, hole transport layer 225 transports holes and injects holes into emissive layer 220, and may be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED may be described as having an “organic layer” disposed between a cathode and an anode. This organic layer may comprise a single layer, or may further comprise multiple layers of different organic materials as described, for example, with respect to FIGS. 1 and 2.

Structures and materials not specifically described may also be used, such as OLEDs comprised of polymeric materials (PLEDs) such as disclosed in U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of further example, OLEDs having a single organic layer may be used. OLEDs may be stacked, for example as described in U.S. Pat. No. 5,707,745 to Forrest et al, which is incorporated by reference in its entirety. The OLED structure may deviate from the simple layered structure illustrated in FIGS. 1 and 2. For example, the substrate may include an angled reflective surface to improve outcoupling, such as a mesa structure as described in U.S. Pat. No. 6,091,195 to Forrest et al., and/or a pit structure as described in U.S. Pat. No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entireties.

Unless otherwise specified, any of the layers of the various embodiments may be deposited by any suitable method. For the organic layers, preferred methods include thermal evaporation, ink-jet, such as described in U.S. Pat. Nos. 6,013,982 and 6,087,196, which are incorporated by reference in their entireties, organic vapor phase deposition (OVPD), such as described in U.S. Pat. No. 6,337,102 to Forrest et al., which is incorporated by reference in its entirety, and deposition by organic vapor jet printing (OVJP), such as described in U.S. Pat. No. 7,431,968, which is incorporated by reference in its entirety. Other suitable deposition methods include spin coating and other solution based processes. Solution based processes are preferably carried out in nitrogen or an inert atmosphere. For the other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding such as described in U.S. Pat. Nos. 6,294,398 and 6,468,819, which are incorporated by reference in their entireties, and patterning associated with some of the deposition methods such as ink jet and OVJD. Other methods may also be used. The materials to be deposited may be modified to make them compatible with a particular deposition method. For example, substituents such as alkyl and aryl groups, branched or unbranched, and preferably containing at least 3 carbons, may be used in small molecules to enhance their ability to undergo solution processing. Substituents having 20 carbons or more may be used, and 3-20 carbons is a preferred range. Materials with asymmetric structures may have better solution processability than those having symmetric structures, because asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents may be used to enhance the ability of small molecules to undergo solution processing.

Devices fabricated in accordance with embodiments of the present invention may further optionally comprise a barrier layer. One purpose of the barrier layer is to protect the electrodes and organic layers from damaging exposure to harmful species in the environment including moisture, vapor and/or gases, etc. The barrier layer may be deposited over, under or next to a substrate, an electrode, or over any other parts of a device including an edge. The barrier layer may comprise a single layer, or multiple layers. The barrier layer may be formed by various known chemical vapor deposition techniques and may include compositions having a single phase as well as compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may incorporate an inorganic or an organic compound or both. The preferred barrier layer comprises a mixture of a polymeric material and a non-polymeric material as described in U.S. Pat. No. 7,968,146, PCT Pat. Application Nos. PCT/US2007/023098 and PCT/US2009/042829, which are herein incorporated by reference in their entireties. To be considered a “mixture”, the aforesaid polymeric and non-polymeric materials comprising the barrier layer should be deposited under the same reaction conditions and/or at the same time. The weight ratio of polymeric to non-polymeric material may be in the range of 95:5 to 5:95. The polymeric material and the non-polymeric material may be created from the same precursor material. In one example, the mixture of a polymeric material and a non-polymeric material consists essentially of polymeric silicon and inorganic silicon.

Devices fabricated in accordance with embodiments of the invention may be incorporated into a wide variety of consumer products, including flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads up displays, fully transparent displays, flexible displays, laser printers, telephones, cell phones, personal digital assistants (PDAs), laptop computers, digital cameras, camcorders, viewfinders, micro-displays, vehicles, a large area wall, theater or stadium screen, or a sign. Various control mechanisms may be used to control devices fabricated in accordance with the present invention, including passive matrix and active matrix. Many of the devices are intended for use in a temperature range comfortable to humans, such as 18 degrees C. to 30 degrees C., and more preferably at room temperature (20-25 degrees C.).

The materials and structures described herein may have applications in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors may employ the materials and structures. More generally, organic devices, such as organic transistors, may employ the materials and structures.

The terms halo, halogen, alkyl, cycloalkyl, alkenyl, alkynyl, arylkyl, heterocyclic group, aryl, aromatic group, and heteroaryl are known to the art, and are defined in U.S. Pat. No. 7,279,704 at cols. 31-32, which are incorporated herein by reference.

It is believed that the internal quantum efficiency (IQE) of fluorescent OLEDs can exceed the 25% spin statistics limit through delayed fluorescence. As used herein, there are two types of delayed fluorescence, i.e. P-type delayed fluorescence and E-type delayed fluorescence. P-type delayed fluorescence is generated from triplet-triplet annihilation (TTA).

On the other hand, E-type delayed fluorescence does not rely on the collision of two triplets, but rather on the thermal population between the triplet states and the singlet excited states. Compounds that are capable of generating E-type delayed fluorescence are required to have very small singlet-triplet gaps. Thermal energy can activate the transition from the triplet state back to the singlet state. This type of delayed fluorescence is also known as thermally activated delayed fluorescence (TADF). A distinctive feature of TADF is that the delayed component increases as temperature rises due to the increased thermal energy. If the reverse intersystem crossing rate is fast enough to minimize the non-radiative decay from the triplet state, the fraction of back populated singlet excited states can potentially reach 75%. The total singlet fraction can be 100%, far exceeding the spin statistics limit for electrically generated excitons.

E-type delayed fluorescence characteristics can be found in an exciplex system or in a single compound. Without being bound by theory, it is believed that E-type delayed fluorescence requires the luminescent material to have a small singlet-triplet energy gap (ΔE_(S-T)). Organic, non-metal containing, donor-acceptor luminescent materials may be able to achieve this. The emission in these materials is often characterized as a donor-acceptor charge-transfer (CT) type emission. The spatial separation of the HOMO and LUMO in these donor-acceptor type compounds often results in small ΔE_(S-T). These states may involve CT states. Often, donor-acceptor luminescent materials are constructed by connecting an electron donor moiety such as amino- or carbazole-derivatives and an electron acceptor moiety such as N-containing six-membered aromatic rings.

A first device comprising a first organic light emitting device comprising an anode, a cathode, and an emissive layer, disposed between the anode and the cathode. The emissive layer comprises a first emitting compound having the formula G¹-Z, Formula I. G¹ is an electron acceptor group and Z is an electron donor group.

Z has the formula:

Formula II, where G² has the structure

and G² is fused to any two adjacent carbon atoms on ring A. X is selected from the group consisting of O, S, and Se. R¹ represents mono-, di-substitution, or no substitution. R², and R³ independently represent mono-, di-, tri-, or tetra-substitution. R¹ is optionally fused to ring A, R² is optionally fused to ring B, and R³ is optionally fused to ring C. R¹, R² and R³ are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

As used herein, the phrase “electron acceptor” means a fragment that can accept electron density from an aromatic system, and the phrase “electron donor” means a fragment that donates electron density into an aromatic system.

In one aspect, G¹ comprises at least one chemical group selected from the group consisting of:

wherein A¹ to A⁶ independently comprise C or N, and at least one of A¹ to A⁶ is N. J¹ to J⁴ independently comprise C or N, and at least one of J¹ to J⁴ is N. X¹ is O, S, or NR. R is selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one embodiment, G¹ comprises at least one chemical group selected from the group consisting of:

E¹ to E⁸ independently comprise C or N, L¹ to L⁴ independently comprise C or N, and X² is O, S, or NR. R is selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one embodiment, R³ is alkyl or aryl. In one embodiment, Z comprises at least one chemical group selected from the group consisting of:

where, R¹¹, R¹², and R¹³ are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one embodiment, Z comprises a least one chemical group selected from the group consisting of:

In one embodiment, G¹ comprises at least one chemical group selected from the group consisting of:

wherein R²¹, R²², and R²³ are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one embodiment, G¹ comprises at least one chemical group selected from the group consisting of:

In one embodiment, G¹ comprises at least one chemical group selected from the group consisting of:

In one embodiment, the compound is selected from the group consisting of:

In one embodiment, the first device emits a luminescent radiation at room temperature when a voltage is applied across the first organic light emitting device, where the luminescent radiation comprises a delayed fluorescent process.

In one embodiment, the emissive layer further comprises a first phosphorescent emitting material.

In one embodiment, the emissive layer further comprises a second phosphorescent emitting material.

In one embodiment, the emissive layer further comprises a host material.

In one embodiment, the first device emits a white light at room temperature when a voltage is applied across the organic light emitting device.

In one embodiment, the first emitting compound emits a blue light having a peak wavelength between about 400 nm to about 500 nm.

In one embodiment, the first emitting compound emits a yellow light having a peak wavelength between about 530 nm to about 580 nm.

In one embodiment, the first device comprises a second organic light-emitting device, wherein the second organic light emitting device is stacked on the first organic light emitting device.

In one embodiment, the first device is a consumer product. In one embodiment, the first device is an organic light-emitting device. In one embodiment, the first device comprises a lighting panel.

In one embodiment, a method of making a first organic light emitting device, comprising depositing an anode on a substrate, depositing at least one organic layer comprising a compound of formula G¹-Z, Formula I. G¹ is an electron acceptor group and Z is an electron donor group.

Z has the formula:

Formula II, where G² has the structure

and G² is fused to any two adjacent carbon atoms on ring A. X is selected from the group consisting of O, S, and Se, R¹ represents mono-, di-substitution, or no substitution. R², and R³ independently represent mono-, di-, tri-, or tetra-substitution. R¹ is optionally fused to ring A, R² is optionally fused to ring B, and R³ is optionally fused to ring C. R¹, R² and R³ are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof, depositing a cathode. The emissive layer is deposited between the anode and cathode.

In one embodiment, the at least one organic layer is deposited using a solution process.

In some embodiments, the compounds of Formula I have the following structures:

Compound Donor Acceptor Number X Side Side 1. S D¹⁰¹ A¹⁰¹ 2. S D¹⁰² A¹⁰¹ 3. S D¹⁰³ A¹⁰¹ 4. S D¹⁰⁴ A¹⁰¹ 5. S D¹⁰⁵ A¹⁰¹ 6. S D¹⁰⁶ A¹⁰¹ 7. S D¹⁰⁷ A¹⁰¹ 8. S D¹⁰⁸ A¹⁰¹ 9. S D¹⁰⁹ A¹⁰¹ 10. S D¹¹⁰ A¹⁰¹ 11. S D¹¹¹ A¹⁰¹ 12. S D¹¹² A¹⁰¹ 13. S D¹⁰¹ A¹⁰² 14. S D¹⁰² A¹⁰² 15. S D¹⁰³ A¹⁰² 16. S D¹⁰⁴ A¹⁰² 17. S D¹⁰⁵ A¹⁰² 18. S D¹⁰⁶ A¹⁰² 19. S D¹⁰⁷ A¹⁰² 20. S D¹⁰⁸ A¹⁰² 21. S D¹⁰⁹ A¹⁰² 22. S D¹¹⁰ A¹⁰² 23. S D¹¹¹ A¹⁰² 24. S D¹¹² A¹⁰² 25. S D¹⁰¹ A¹⁰³ 26. S D¹⁰² A¹⁰³ 27. S D¹⁰³ A¹⁰³ 28. S D¹⁰⁴ A¹⁰³ 29. S D¹⁰⁵ A¹⁰³ 30. S D¹⁰⁶ A¹⁰³ 31. S D¹⁰⁷ A¹⁰³ 32. S D¹⁰⁸ A¹⁰³ 33. S D¹⁰⁹ A¹⁰³ 34. S D¹¹⁰ A¹⁰³ 35. S D¹¹¹ A¹⁰³ 36. S D¹¹² A¹⁰³ 37. S D¹⁰¹ A¹⁰⁴ 38. S D¹⁰² A¹⁰⁴ 39. S D¹⁰³ A¹⁰⁴ 40. S D¹⁰⁴ A¹⁰⁴ 41. S D¹⁰⁵ A¹⁰⁴ 42. S D¹⁰⁶ A¹⁰⁴ 43. S D¹⁰⁷ A¹⁰⁴ 44. S D¹⁰⁸ A¹⁰⁴ 45. S D¹⁰⁹ A¹⁰⁴ 46. S D¹¹⁰ A¹⁰⁴ 47. S D¹¹¹ A¹⁰⁴ 48. S D¹¹² A¹⁰⁴ 49. S D¹⁰¹ A¹⁰⁵ 50. S D¹⁰² A¹⁰⁵ 51. S D¹⁰³ A¹⁰⁵ 52. S D¹⁰⁴ A¹⁰⁵ 53. S D¹⁰⁵ A¹⁰⁵ 54. S D¹⁰⁶ A¹⁰⁵ 55. S D¹⁰⁷ A¹⁰⁵ 56. S D¹⁰⁸ A¹⁰⁵ 57. S D¹⁰⁹ A¹⁰⁵ 58. S D¹¹⁰ A¹⁰⁵ 59. S D¹¹¹ A¹⁰⁵ 60. S D¹¹² A¹⁰⁵ 61. S D¹⁰¹ A¹⁰⁶ 62. S D¹⁰² A¹⁰⁶ 63. S D¹⁰³ A¹⁰⁶ 64. S D¹⁰⁴ A¹⁰⁶ 65. S D¹⁰⁵ A¹⁰⁶ 66. S D¹⁰⁶ A¹⁰⁶ 67. S D¹⁰⁷ A¹⁰⁶ 68. S D¹⁰⁸ A¹⁰⁶ 69. S D¹⁰⁹ A¹⁰⁶ 70. S D¹¹⁰ A¹⁰⁶ 71. S D¹¹¹ A¹⁰⁶ 72. S D¹¹² A¹⁰⁶ 73. S D¹⁰¹ A¹⁰⁷ 74. S D¹⁰² A¹⁰⁷ 75. S D¹⁰³ A¹⁰⁷ 76. S D¹⁰⁴ A¹⁰⁷ 77. S D¹⁰⁵ A¹⁰⁷ 78. S D¹⁰⁶ A¹⁰⁷ 79. S D¹⁰⁷ A¹⁰⁷ 80. S D¹⁰⁸ A¹⁰⁷ 81. S D¹⁰⁹ A¹⁰⁷ 82. S D¹¹⁰ A¹⁰⁷ 83. S D¹¹¹ A¹⁰⁷ 84. S D¹¹² A¹⁰⁷ 85. S D¹⁰¹ A¹⁰⁸ 86. S D¹⁰² A¹⁰⁸ 87. S D¹⁰³ A¹⁰⁸ 88. S D¹⁰⁴ A¹⁰⁸ 89. S D¹⁰⁵ A¹⁰⁸ 90. S D¹⁰⁶ A¹⁰⁸ 91. S D¹⁰⁷ A¹⁰⁸ 92. S D¹⁰⁸ A¹⁰⁸ 93. S D¹⁰⁹ A¹⁰⁸ 94. S D¹¹⁰ A¹⁰⁸ 95. S D¹¹¹ A¹⁰⁸ 96. S D¹¹² A¹⁰⁸ 97. S D¹⁰¹ A¹⁰⁹ 98. S D¹⁰² A¹⁰⁹ 99. S D¹⁰³ A¹⁰⁹ 100. S D¹⁰⁴ A¹⁰⁹ 101. S D¹⁰⁵ A¹⁰⁹ 102. S D¹⁰⁶ A¹⁰⁹ 103. S D¹⁰⁷ A¹⁰⁹ 104. S D¹⁰⁸ A¹⁰⁹ 105. S D¹⁰⁹ A¹⁰⁹ 106. S D¹¹⁰ A¹⁰⁹ 107. S D¹¹¹ A¹⁰⁹ 108. S D¹¹² A¹⁰⁹ 109. S D¹⁰¹ A¹¹⁰ 110. S D¹⁰² A¹¹⁰ 111. S D¹⁰³ A¹¹⁰ 112. S D¹⁰⁴ A¹¹⁰ 113. S D¹⁰⁵ A¹¹⁰ 114. S D¹⁰⁶ A¹¹⁰ 115. S D¹⁰⁷ A¹¹⁰ 116. S D¹⁰⁸ A¹¹⁰ 117. S D¹⁰⁹ A¹¹⁰ 118. S D¹¹⁰ A¹¹⁰ 119. S D¹¹¹ A¹¹⁰ 120. S D¹¹² A¹¹⁰ 121. S D¹⁰¹ A¹¹¹ 122. S D¹⁰² A¹¹¹ 123. S D¹⁰³ A¹¹¹ 124. S D¹⁰⁴ A¹¹¹ 125. S D¹⁰⁵ A¹¹¹ 126. S D¹⁰⁶ A¹¹¹ 127. S D¹⁰⁷ A¹¹¹ 128. S D¹⁰⁸ A¹¹¹ 129. S D¹⁰⁹ A¹¹¹ 130. S D¹¹⁰ A¹¹¹ 131. S D¹¹¹ A¹¹¹ 132. S D¹¹² A¹¹¹ 133. S D¹⁰¹ A¹¹² 134. S D¹⁰² A¹¹² 135. S D¹⁰³ A¹¹² 136. S D¹⁰⁴ A¹¹² 137. S D¹⁰⁵ A¹¹² 138. S D¹⁰⁶ A¹¹² 139. S D¹⁰⁷ A¹¹² 140. S D¹⁰⁸ A¹¹² 141. S D¹⁰⁹ A¹¹² 142. S D¹¹⁰ A¹¹² 143. S D¹¹¹ A¹¹² 144. S D¹¹² A¹¹² 145. S D¹⁰¹ A¹¹³ 146. S D¹⁰² A¹¹³ 147. S D¹⁰³ A¹¹³ 148. S D¹⁰⁴ A¹¹³ 149. S D¹⁰⁵ A¹¹³ 150. S D¹⁰⁶ A¹¹³ 151. S D¹⁰⁷ A¹¹³ 152. S D¹⁰⁸ A¹¹³ 153. S D¹⁰⁹ A¹¹³ 154. S D¹¹⁰ A¹¹³ 155. S D¹¹¹ A¹¹³ 156. S D¹¹² A¹¹³ 157. O D¹⁰¹ A¹⁰¹ 158. O D¹⁰² A¹⁰¹ 159. O D¹⁰³ A¹⁰¹ 160. O D¹⁰⁴ A¹⁰¹ 161. O D¹⁰⁵ A¹⁰¹ 162. O D¹⁰⁶ A¹⁰¹ 163. O D¹⁰⁷ A¹⁰¹ 164. O D¹⁰⁸ A¹⁰¹ 165. O D¹⁰⁹ A¹⁰¹ 166. O D¹¹⁰ A¹⁰¹ 167. O D¹¹¹ A¹⁰¹ 168. O D¹¹² A¹⁰¹ 169. O D¹⁰¹ A¹⁰² 170. O D¹⁰² A¹⁰² 171. O D¹⁰³ A¹⁰² 172. O D¹⁰⁴ A¹⁰² 173. O D¹⁰⁵ A¹⁰² 174. O D¹⁰⁶ A¹⁰² 175. O D¹⁰⁷ A¹⁰² 176. O D¹⁰⁸ A¹⁰² 177. O D¹⁰⁹ A¹⁰² 178. O D¹¹⁰ A¹⁰² 179. O D¹¹¹ A¹⁰² 180. O D¹¹² A¹⁰² 181. O D¹⁰¹ A¹⁰³ 182. O D¹⁰² A¹⁰³ 183. O D¹⁰³ A¹⁰³ 184. O D¹⁰⁴ A¹⁰³ 185. O D¹⁰⁵ A¹⁰³ 186. O D¹⁰⁶ A¹⁰³ 187. O D¹⁰⁷ A¹⁰³ 188. O D¹⁰⁸ A¹⁰³ 189. O D¹⁰⁹ A¹⁰³ 190. O D¹¹⁰ A¹⁰³ 191. O D¹¹¹ A¹⁰³ 192. O D¹¹² A¹⁰³ 193. O D¹⁰¹ A¹⁰⁴ 194. O D¹⁰² A¹⁰⁴ 195. O D¹⁰³ A¹⁰⁴ 196. O D¹⁰⁴ A¹⁰⁴ 197. O D¹⁰⁵ A¹⁰⁴ 198. O D¹⁰⁶ A¹⁰⁴ 199. O D¹⁰⁷ A¹⁰⁴ 200. O D¹⁰⁸ A¹⁰⁴ 201. O D¹⁰⁹ A¹⁰⁴ 202. O D¹¹⁰ A¹⁰⁴ 203. O D¹¹¹ A¹⁰⁴ 204. O D¹¹² A¹⁰⁴ 205. O D¹⁰¹ A¹⁰⁵ 206. O D¹⁰² A¹⁰⁵ 207. O D¹⁰³ A¹⁰⁵ 208. O D¹⁰⁴ A¹⁰⁵ 209. O D¹⁰⁵ A¹⁰⁵ 210. O D¹⁰⁶ A¹⁰⁵ 211. O D¹⁰⁷ A¹⁰⁵ 212. O D¹⁰⁸ A¹⁰⁵ 213. O D¹⁰⁹ A¹⁰⁵ 214. O D¹¹⁰ A¹⁰⁵ 215. O D¹¹¹ A¹⁰⁵ 216. O D¹¹² A¹⁰⁵ 217. O D¹⁰¹ A¹⁰⁶ 218. O D¹⁰² A¹⁰⁶ 219. O D¹⁰³ A¹⁰⁶ 220. O D¹⁰⁴ A¹⁰⁶ 221. O D¹⁰⁵ A¹⁰⁶ 222. O D¹⁰⁶ A¹⁰⁶ 223. O D¹⁰⁷ A¹⁰⁶ 224. O D¹⁰⁸ A¹⁰⁶ 225. O D¹⁰⁹ A¹⁰⁶ 226. O D¹¹⁰ A¹⁰⁶ 227. O D¹¹¹ A¹⁰⁶ 228. O D¹¹² A¹⁰⁶ 229. O D¹⁰¹ A¹⁰⁷ 230. O D¹⁰² A¹⁰⁷ 231. O D¹⁰³ A¹⁰⁷ 232. O D¹⁰⁴ A¹⁰⁷ 233. O D¹⁰⁵ A¹⁰⁷ 234. O D¹⁰⁶ A¹⁰⁷ 235. O D¹⁰⁷ A¹⁰⁷ 236. O D¹⁰⁸ A¹⁰⁷ 237. O D¹⁰⁹ A¹⁰⁷ 238. O D¹¹⁰ A¹⁰⁷ 239. O D¹¹¹ A¹⁰⁷ 240. O D¹¹² A¹⁰⁷ 241. O D¹⁰¹ A¹⁰⁸ 242. O D¹⁰² A¹⁰⁸ 243. O D¹⁰³ A¹⁰⁸ 244. O D¹⁰⁴ A¹⁰⁸ 245. O D¹⁰⁵ A¹⁰⁸ 246. O D¹⁰⁶ A¹⁰⁸ 247. O D¹⁰⁷ A¹⁰⁸ 248. O D¹⁰⁸ A¹⁰⁸ 249. O D¹⁰⁹ A¹⁰⁸ 250. O D¹¹⁰ A¹⁰⁸ 251. O D¹¹¹ A¹⁰⁸ 252. O D¹¹² A¹⁰⁸ 253. O D¹⁰¹ A¹⁰⁹ 254. O D¹⁰² A¹⁰⁹ 255. O D¹⁰³ A¹⁰⁹ 256. O D¹⁰⁴ A¹⁰⁹ 257. O D¹⁰⁵ A¹⁰⁹ 258. O D¹⁰⁶ A¹⁰⁹ 259. O D¹⁰⁷ A¹⁰⁹ 260. O D¹⁰⁸ A¹⁰⁹ 261. O D¹⁰⁹ A¹⁰⁹ 262. 0 D¹¹⁰ A¹⁰⁹ 263. O D¹¹¹ A¹⁰⁹ 264. O D¹¹² A¹⁰⁹ 265. O D¹⁰¹ A¹¹⁰ 266. O D¹⁰² A¹¹⁰ 267. O D¹⁰³ A¹¹⁰ 268. O D¹⁰⁴ A¹¹⁰ 269. O D¹⁰⁵ A¹¹⁰ 270. O D¹⁰⁶ A¹¹⁰ 271. O D¹⁰⁷ A¹¹⁰ 272. O D¹⁰⁸ A¹¹⁰ 273. O D¹⁰⁹ A¹¹⁰ 274. O D¹¹⁰ A¹¹⁰ 275. O D¹¹¹ A¹¹⁰ 276. O D¹¹² A¹¹⁰ 277. O D¹⁰¹ A¹¹¹ 278. O D¹⁰² A¹¹¹ 279. O D¹⁰³ A¹¹¹ 280. O D¹⁰⁴ A¹¹¹ 281. O D¹⁰⁵ A¹¹¹ 282. O D¹⁰⁶ A¹¹¹ 283. O D¹⁰⁷ A¹¹¹ 284. O D¹⁰⁸ A¹¹¹ 285. O D¹⁰⁹ A¹¹¹ 286. O D¹¹⁰ A¹¹¹ 287. O D¹¹¹ A¹¹¹ 288. O D¹¹² A¹¹¹ 289. O D¹⁰¹ A¹¹² 290. O D¹⁰² A¹¹² 291. O D¹⁰³ A¹¹² 292. O D¹⁰⁴ A¹¹² 293. O D¹⁰⁵ A¹¹² 294. O D¹⁰⁶ A¹¹² 295. O D¹⁰⁷ A¹¹² 296. O D¹⁰⁸ A¹¹² 297. O D¹⁰⁹ A¹¹² 298. O D¹¹⁰ A¹¹² 299. O D¹¹¹ A¹¹² 300. O D¹¹² A¹¹² 301. O D¹⁰¹ A¹¹³ 302. O D¹⁰² A¹¹³ 303. O D¹⁰³ A¹¹³ 304. O D¹⁰⁴ A¹¹³ 305. O D¹⁰⁵ A¹¹³ 306. O D¹⁰⁶ A¹¹³ 307. O D¹⁰⁷ A¹¹³ 308. O D¹⁰⁸ A¹¹³ 309. O D¹⁰⁹ A¹¹³ 310. O D¹¹⁰ A¹¹³ 311. O D¹¹¹ A¹¹³ 312. O D¹¹² A¹¹³

Device Examples

All example devices were fabricated by high vacuum (<10⁻⁷ Torr) thermal evaporation. The anode electrode is 800 Å of indium tin oxide (ITO). The cathode consisted of 10 Å of LiF followed by 1,000 Å of Al. All devices are encapsulated with a glass lid sealed with an epoxy resin in a nitrogen glove box (<1 ppm of H₂O and O₂) immediately after fabrication, and a moisture getter was incorporated inside the package.

The example devices have the following architectures:

Device 1=ITO/TAPC (400 Å)/Compound 1 (200 Å)/TmPyPB (500 Å)/LiF/Al

Device 2=ITO/TAPC (400 Å)/Host1:Compound1 (20%, 200 Å)/TmPyPB (500 Å)/LiF/Al

The structures of TAPC, TmPyPB, and Host 1 are shown below:

TABLE 1 Performance of electroluminescent device 1-2 using Compound 1 as emitting material Maximum EQE @1000 nits Device # λ_(max) L LE_(max) EQE_(max) Voltage LE EQE Device x y (nm) nits V (V) (cd/A) (%) (V) (cd/A) (%) 1 0.306 0.518 518 100 6 10.7 3.8 8 8.8 3.0 2 0.281 0.495 512 330 6.5 10 3.4 8.9 7.3 2.6

Device 1 was fabricated using TAPC as the HIL/HTL, a neat layer of Compound 1 as the EML, and TmPyPB as the ETL. The results are shown in table 1. Green emission with a λ_(max) of 518 nm and CIE of (0.306, 0.518) was observed from the device, which is in good agreement with the photoluminescence. The maximum external quantum efficiency (EQE) was 3.8% that was observed at the brightness of 100 nits. The maximum luminous efficiency (LE) was 10.7 cd/A at the same brightness. At 1000 nits, the EQE and LE were 3% and 8.8 cd/A, respectively.

The measured photoluminescence quantum yield (PLQY) of the 5% PMMA film of Compound 1 was approximately 18% (PL quantum efficiency measurements were carried out on a Hamamatsu C9920 system equipped with a xenon lamp, integrating sphere and a model C10027 photonic multi-channel analyzer). For a standard fluorescent OLED with only prompt singlet emission, the theoretical percentage of singlet excitons is 25%. The outcoupling efficiency of a bottom-emitting lambertian OLED is considered to be around 20-25%. Therefore, for a fluorescent emitter having a PLQY of 20% without delayed fluorescence, the highest EQE should not exceed 1.2% based on the statistical value of 25% electrically generated singlet excitons. The devices with compounds of Formula I, such as Compound 1, as the emitter showed EQE far exceeding the theoretic limit even with a non-optimal device structure.

Device 2 was fabricated using Host1 as the host matrix with Compound 1 doped at 20 wt %. Similar efficiencies were observed for the doped device. Once again, the EQE exceeded the theoretic limit of pure fluorescent devices even with a non-optimal device structure.

Combination with Other Materials

The materials described herein as useful for a particular layer in an organic light emitting device may be used in combination with a wide variety of other materials present in the device. For example, emissive dopants disclosed herein may be used in conjunction with a wide variety of hosts, transport layers, blocking layers, injection layers, electrodes and other layers that may be present. The materials described or referred to below are non-limiting examples of materials that may be useful in combination with the compounds disclosed herein, and one of skill in the art can readily consult the literature to identify other materials that may be useful in combination.

HIL/HTL:

A hole injecting/transporting material to be used in the present invention is not particularly limited, and any compound may be used as long as the compound is typically used as a hole injecting/transporting material. Examples of the material include, but not limit to: a phthalocyanine or porphryin derivative; an aromatic amine derivative; an indolocarbazole derivative; a polymer containing fluorohydrocarbon; a polymer with conductivity dopants; a conducting polymer, such as PEDOT/PSS; a self-assembly monomer derived from compounds such as phosphonic acid and silane derivatives; a metal oxide derivative, such as MoO_(x); a p-type semiconducting organic compound, such as 1,4,5,8,9,12-Hexaazatriphenylenehexacarbonitrile; a metal complex, and a cross-linkable compounds.

Examples of aromatic amine derivatives used in HIL or HTL include, but not limit to the following general structures:

Each of Ar¹ to Ar⁹ is selected from the group consisting aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, azulene; group consisting aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and group consisting 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Wherein each Ar is further substituted by a substituent selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, Ar¹ to Ar⁹ is independently selected from the group consisting of:

k is an integer from 1 to 20; X¹⁰¹ to X¹⁰⁸ is C (including CH) or N; Z¹⁰¹ is NAr¹, O, or S; Ar¹ has the same group defined above.

Examples of metal complexes used in HIL or HTL include, but not limit to the following general formula:

Met is a metal; (Y¹⁰¹-Y¹⁰²) is a bidentate ligand, Y¹⁰¹ and Y¹⁰² are independently selected from C, N, O, P, and S; L¹⁰¹ is another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal.

In one aspect, (Y¹⁰¹-Y¹⁰²) is a 2-phenylpyridine derivative.

In another aspect, (Y¹⁰¹-Y¹⁰²) is a carbene ligand.

In another aspect, Met is selected from Ir, Pt, Os, and Zn.

In a further aspect, the metal complex has a smallest oxidation potential in solution vs. Fc⁺/Fc couple less than about 0.6 V.

Host:

The light emitting layer of the organic EL device of the present invention preferably contains at least a metal complex as light emitting material, and may contain a host material using the metal complex as a dopant material. Examples of the host material are not particularly limited, and any metal complexes or organic compounds may be used as long as the triplet energy of the host is larger than that of the dopant. While the Table below categorizes host materials as preferred for devices that emit various colors, any host material may be used with any dopant so long as the triplet criteria is satisfied.

Examples of metal complexes used as host are preferred to have the following general formula:

Met is a metal; (Y¹⁰³-Y¹⁰⁴) is a bidentate ligand, Y¹⁰³ and Y¹⁰⁴ are independently selected from C, N, O, P, and S; L¹⁰¹ is another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal; and k′+k″ is the maximum number of ligands that may be attached to the metal.

In one aspect, the metal complexes are:

(O—N) is a bidentate ligand, having metal coordinated to atoms O and N.

In another aspect, Met is selected from Ir and Pt.

In a further aspect, (Y¹⁰³-Y¹⁰⁴) is a carbene ligand.

Examples of organic compounds used as host are selected from the group consisting aromatic hydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, azulene; group consisting aromatic heterocyclic compounds such as dibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene, benzoselenophene, carbazole, indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine, thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine; and group consisting 2 to 10 cyclic structural units which are groups of the same type or different types selected from the aromatic hydrocarbon cyclic group and the aromatic heterocyclic group and are bonded to each other directly or via at least one of oxygen atom, nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom, chain structural unit and the aliphatic cyclic group. Wherein each group is further substituted by a substituent selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In one aspect, host compound contains at least one of the following groups in the molecule:

R¹⁰¹ to R¹⁰⁷ is independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof, when it is aryl or heteroaryl, it has the similar definition as Ar's mentioned above.

k is an integer from 1 to 20; k′″ is an integer from 0 to 20.

X¹⁰¹ to X¹⁰⁸ is selected from C (including CH) or N.

Z¹⁰¹ and Z¹⁰² is selected from NR¹⁰¹, O, or S.

HBL:

A hole blocking layer (HBL) may be used to reduce the number of holes and/or excitons that leave the emissive layer. The presence of such a blocking layer in a device may result in substantially higher efficiencies as compared to a similar device lacking a blocking layer. Also, a blocking layer may be used to confine emission to a desired region of an OLED.

In one aspect, compound used in HBL contains the same molecule or the same functional groups used as host described above.

In another aspect, compound used in HBL contains at least one of the following groups in the molecule:

k is an integer from 1 to 20; L¹⁰¹ is another ligand, k′ is an integer from 1 to 3.

ETL:

Electron transport layer (ETL) may include a material capable of transporting electrons. Electron transport layer may be intrinsic (undoped), or doped. Doping may be used to enhance conductivity. Examples of the ETL material are not particularly limited, and any metal complexes or organic compounds may be used as long as they are typically used to transport electrons.

In one aspect, compound used in ETL contains at least one of the following groups in the molecule:

R¹⁰¹ is selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof, when it is aryl or heteroaryl, it has the similar definition as Ar's mentioned above.

Ar¹ to Ar³ has the similar definition as Ar's mentioned above.

k is an integer from 1 to 20.

X¹⁰¹ to X¹⁰⁸ is selected from C (including CH) or N.

In another aspect, the metal complexes used in ETL contains, but not limit to the following general formula:

(O—N) or (N—N) is a bidentate ligand, having metal coordinated to atoms O, N or N, N; L¹⁰¹ is another ligand; k′ is an integer value from 1 to the maximum number of ligands that may be attached to the metal.

In any above-mentioned compounds used in each layer of the OLED device, the hydrogen atoms can be partially or fully deuterated. Thus, any specifically listed substituent, such as, without limitation, methyl, phenyl, pyridyl, etc. encompasses undeuterated, partially deuterated, and fully deuterated versions thereof. Similarly, classes of substituents such as, without limitation, alkyl, aryl, cycloalkyl, heteroaryl, etc. also encompass undeuterated, partially deuterated, and fully deuterated versions thereof.

In addition to and/or in combination with the materials disclosed herein, many hole injection materials, hole transporting materials, host materials, dopant materials, exciton/hole blocking layer materials, electron transporting and electron injecting materials may be used in an OLED. Non-limiting examples of the materials that may be used in an OLED in combination with materials disclosed herein are listed in Table 2 below. Table 2 lists non-limiting classes of materials, non-limiting examples of compounds for each class, and references that disclose the materials.

TABLE 2 MATERIAL EXAMPLES OF MATERIAL PUBLICATIONS Hole injection materials Phthalocyanine and porphryin compounds

Appl. Phys. Lett. 69, 2160 (1996) Starburst triarylamines

J. Lumin. 72-74, 985 (1997) CF_(x) Fluorohydrocarbon polymer

Appl. Phys. Lett. 78, 673 (2001) Conducting polymers (e.g., PEDOT:PSS, polyaniline, polypthiophene)

Synth. Met. 87, 171 (1997) WO2007002683 Phosphonic acid and sliane SAMs

US20030162053 Triarylamine or polythiophene polymers with conductivity dopants

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EXPERIMENTAL

It is understood that the various embodiments described herein are by way of example only, and are not intended to limit the scope of the invention. For example, many of the materials and structures described herein may be substituted with other materials and structures without deviating from the spirit of the invention. The present invention as claimed may therefore include variations from the particular examples and preferred embodiments described herein, as will be apparent to one of skill in the art. It is understood that various theories as to why the invention works are not intended to be limiting. 

The invention claimed is:
 1. A first device comprising a first organic light emitting device, comprising: an anode; a cathode; and an emissive layer, disposed between the anode and the cathode; wherein the emissive layer comprises a host material doped with a first emitting compound, wherein the first emitting compound has a structure of formula I: G¹-Z,  Formula I; wherein G¹ is an electron acceptor group; and wherein Z is an electron donor group; wherein Z has the formula:

wherein G² has the structure

and wherein G² is fused to any two adjacent carbon atoms on ring A; wherein X is selected from the group consisting of O, S, and Se; wherein R¹ represents mono-, di-substitution, or no substitution; wherein R², and R³ independently represent mono-, di-, tri-, or tetra-substitution; wherein R¹ is optionally fused to ring A, R² is optionally fused to ring B, and R³ is optionally fused to ring C; and wherein R¹, R² and R³ are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.
 2. The first device of claim 1, wherein G¹ comprises at least one chemical group selected from the group consisting of:

wherein A¹ to A⁶ independently comprise C or N, and at least one of A¹ to A⁶ is N; wherein J¹ to J⁴ independently comprise C or N, and at least one of J¹ to J⁴ is N; wherein X¹ is O, S, or NR; wherein R is selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.
 3. The first device of claim 1, wherein G¹ comprises at least one chemical group selected from the group consisting of:

wherein E¹ to E⁸ independently comprise C or N; wherein L¹ to L⁴ independently comprise C or N; wherein X² is O, S, or NR; and wherein R is selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.
 4. The first device of claim 1, wherein R³ is alkyl or aryl.
 5. The first device of claim 1, wherein Z comprises at least one chemical group selected from the group consisting of:

wherein R¹¹, R¹², and R¹³ are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.
 6. The first device of claim 1, wherein Z comprises a least one chemical group selected from the group consisting of:


7. The first device of claim 1, wherein G¹ comprises at least one chemical group selected from the group consisting of:

wherein R²¹, R²², and R²³ are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.
 8. The first device of claim 1, wherein G¹ comprises at least one chemical group selected from the group consisting of:


9. The first device of claim 1, wherein G¹ comprises at least one chemical group selected from the group consisting of:


10. The first device of claim 1, wherein the compound is selected from the group consisting of:


11. The first device of claim 1, wherein the first device emits a luminescent radiation at room temperature when a voltage is applied across the first organic light emitting device; wherein the luminescent radiation comprises a delayed fluorescent process.
 12. The first device of claim 11, wherein the emissive layer further comprises a first phosphorescent emitting material.
 13. The first device of claim 12, wherein the emissive layer further comprises a second phosphorescent emitting material.
 14. The first device of claim 12, wherein the first device emits a white light at room temperature when a voltage is applied across the organic light emitting device.
 15. The first device of claim 14, wherein the first emitting compound emits a blue light having a peak wavelength between about 400 nm to about 500 nm.
 16. The first device of claim 14, wherein the first emitting compound emits a yellow light having a peak wavelength between about 530 nm to about 580 nm.
 17. The first device of claim 1, wherein the first device comprises a second organic light-emitting device; wherein the second organic light emitting device is stacked on the first organic light emitting device.
 18. The first device of claim 1, wherein the first device is a consumer product.
 19. The first device of claim 1, wherein the first device is an organic light-emitting device.
 20. The first device of claim 1, wherein the first device comprises a lighting panel.
 21. A method of making a first organic light emitting device, comprising: depositing an anode on a substrate; depositing at least one organic layer comprising a host material doped with a first emitting compound, wherein the first emitting compound has a structure of formula I: G¹-Z,  Formula I; wherein G¹ is an electron acceptor group; and wherein Z is an electron donor group; wherein Z has the formula:

wherein G² has the structure

and wherein G² is fused to any two adjacent carbon atoms on ring A; wherein X is selected from the group consisting of O, S, and Se; wherein R¹ represents mono-, di-substitution, or no substitution; wherein R², and R³ independently represent mono-, di-, tri-, or tetra-substitution; wherein R¹ is optionally fused to ring A, R² is optionally fused to ring B, and R³ is optionally fused to ring C; and wherein R¹, R² and R³ are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfanyl, sulfonyl, phosphino, and combinations thereof; depositing a cathode; wherein the emissive layer is deposited between the anode and cathode.
 22. The method of claim 21, wherein the at least one organic layer is deposited using a solution process. 